What Causes the Musty Smell When Turning on the Car Air Conditioner?

[VivienneFitz]

The following are the reasons why the air conditioner produces an unpleasant odor: 1. The interior environment and air contain odors: For example, airborne dust particles, bacteria, dirt, smoke, etc., are drawn into the air conditioner's filter during cooling. Some fine dust particles pass through the filter and adhere to the evaporator. When the air conditioner is turned off, the high temperature inside the car in summer causes condensation on the evaporator, which reacts with the dust and leads to mold growth. When the air conditioner is turned on again, the musty smell from the moldy dust is blown out, resulting in an unpleasant odor in the car. 2. Regular cleaning of the filter: By cleaning the filter regularly (every 15 days) and maintaining good ventilation inside the car to keep the air clean and fresh, or by frequently spraying disinfectant air fresheners on the filter and evaporator of the car's air conditioner, the odor can be eliminated.